Mixing apparatus



Jun 10, 196 9 o. R. WICKEVS 3,443,954

MIXING APPARATUS Filed May 17, 1968 United States Patent 3,448,964 MIXING APPARATUS David R. Wickes, 1720 Edgebrook Drive, Rockford, Ill. 61111 Filed May '17, 1968, Ser. No. 730,043 Int. Cl. B01f 9/00 US. Cl. 259-72 Claims ABSTRACT OF THE DISCLOSURE An apparatus for mixing liquid materials in a closed container, in which the container is mounted on a housing supported for movement in a generally horizontal orbit, and orbital movement of the housing and container is produced by an air impelled weight element rolling in an annular raceway in the housing.

The present invention relates to an apparatus for mixing liquid materials and particularly liquid coating materials having a liquid vehicle and a pigment, which liquid coating materials include paints, lacquers, enamels, and the like, herein sometimes generally referred to as liquid coating materials. The apparatus is arranged to mix the liquid vehicle and pigment while the liquid coating materials are in a closed container and without necessitating introduction of a stirring device into the container. As it is well known, the pigments tend to settle out from the liquid vehicle upon standing. It has been found that relatively rapid remixing of the pigment and vehicle can be efiected by rapidly moving the container of liquid material in a circular orbit while constraining the container from rotation about its axis to thereby cause a rapid swirling of the liquid material in the container. This swirling of the liquid material in the container tends to scrub the solid pigment which has settled on the bottom of the container and remix the solids with the vehicle. The container is directly mounted on a housing supported for limited translatory movement in an orbital path and a weight element is mounted for rolling movement in a circular raceway in the housing and impelled by a high velocity air stream to produce an unsymmetrical centrifugal force that tends to move the housing and container in orbital path.

An important object of this invention is to provide an apparatus for mixing liquid materials in a closed container which produces a rapid swirling of the liquid material in the container to agitate and remix the solid materials which may have settled out of the liquid vehicle.

Another object of this invention is to provide an apparatus for mixing liquid materials which is of simple and economical construction; which is quiet in operation, and which avoids use of mechanical type eccentric drives which are subject to high stresses and wear.

A further object of this invention is to provide an apparatus for mixing liquid material in which translatory orbital movement is directly imparted to the container for the liquid material by clamping the container to a housing supported for translatory orbital movement and having a rolling air-impelled weight element therein to produce an unsymmetrical centrifugal force on the housing.

These, together with other objects and advantages of this invention will become apparent from the following description wherein:

FIGURE 1 is a perspective view of a mixing apparatus constructed in accordance with the present invention;

FIGURE 2 is a vertical section view taken on the plane 2-2 of FIGURE 1; and

FIGURE 3 is a horizontal sectional view taken on the plane 3-3 of FIGURE 2.

The mixing apparatus of the present invention is in- Patented June 10, 1969 tended for use in mixing liquid materials and particularly liquid coating materials having a liquid vehicle and a pigment and including paints, lacquers, enamels, etc., herein generally referred to as liquid coating materials. The mixing apparatus in general includes a base 10, a housing 11 having an annular raceway 12 therein and resiliently supported on the base by posts 13 for translatory movement in a generally horizontal orbit relative to the base. A rolling weight element 15 is disposed in the race- Way and an air nozzle or orifice 16 is arranged to direct an air jet into the raceway in a direction to impel the rolling weight element at a high velocity around the raceway to thereby produce an unsymmetrical centrifugal force rotating in a generally horizontal plane and tending to shift the housing horizontally in a direction that follows the rotating centrifugal force. A clamp apparatus 18 is provided for clamping a container 19 of liquid material to the housing 11 for translatory movement therewith. The translatory movement of the container with the housing in a generally horizontal orbit produces a swirling of the liquid material in the housing as illustrated in FIGURE 1 and the swirling liquid vehicle tends to loosen and intermix the solid material or pigments with the liquid vehicle.

The base 10 may be attached to a fixed supporting surface indicated at S in any suitable manner as by fasteners 23 to constrain the base against motion during operation of the device. The housing 11 with the annular raceway 12 is conveniently formed in two opposed sections designated 11a and 11b of generally rectangular outline, and support posts 13 for mounting the housing on the base are preferably attached to the housing at points spaced outwardly a substantial distance from the raceway. The support posts 13 are made laterally resilient to allow resilient horizontal shifting of the housing relative to the base and preferably have a relatively low axial resilience to minimize vertical oscillation of the housing. In the preferred embodiment illustrated, the posts 13 are formed of an elastomeric material 13a such as rubber and having rigid end-fittings 13b imbedded in opposite ends for receiving mounting fasteners 10a and 10b. The fasteners 10b are preferably arranged to extend through aligned openings in the housing sections 1101 and 11b to also hold the housing sections in assembled relation. In order to minimize air consumption the annular raceway 12 is preferably in the form of a toroidal chamber of circular cross-section and the rolling weight element 15 in the form of a sphere having a diameter slightly smaller than the cross-section of the chamber. For example, the chamber 12 can have a cross-section of the order of 1% inches in diameter and the ball element conveniently formed of steel can have a diameter of the order of 1%; inches to provide free rolling of the ball element in the chamber while maintaining a relatively close running seal between the ball element and chamber. The ball element is impelled around the chamber at a relatively high velocity, for example of the order of 1,0002,000 r.p.m., by an air jet from the inlet nozzle orifice 16. The inlet nozzle or orifice can conveniently be formed as a drilled hole 16a in one of the housing sections and, as best shown in FIGURE 3, is arranged to direct an air jet generally tangent to the center line of the toroidal chamber to thereby impel the rolling weight element 15 around the chamber. The nozzle 16 is connected as through a fitting 28 and flexible line 29 to a supply source 31 of compressed air. The mixing apparatus is especially adapted for use in auto-body shops for mixing the liquid coating material used in auto refinishing and the source of compressed air can conveniently be the same source as is used for operating the spray equipment. An exhaust outlet 32 is also arranged to communicate with the annular chamber. The exhaust outlet can be located at any convenient location spaced from the inlet and, as

shown in FIGURE 3, communicates with the chamber at a point spaced substantially greater than 180 measured in the direction of rotation of the ball element from the inlet nozzle 16a. In order to minimize noise, a mufiier 34 can be provided and connected to the. exhaust outlet 32 through a fitting 35.

The container 19 containing the liquid material to be mixed is clamped directly to the housing 11 for translatory movement therewith. The housing 11 has a container support surface 11c at the upper side and the clamp apparatus 18 is conveniently in the form of a U-shaped frame having spaced legs 18a and cross members 18]) at the upper end. A clamp conveniently in the form of a screw 38 is threadedly mounted on the cross members and has a clamp-head 39 arranged to engage the upper end of the container. A handle or knob 40 is provided for manually adjusting the clamp-head. As will be seen from FIGURES 1 and 2, the U-shaped frame extends generally diagonally of the housing across the center thereof and the clamp screw 38 is located generally coaxial with the annular raceway 12. The container 19, preferably of cylindrical construction, is clamped to the upper surface of the housing with the container axis adjacent to or coaxial with the axis of the annular trackway. Thus, the translatory movement of the housing in a generally horizontal orbit produces a corresponding translatory movement of the container in a generally horizontal orbit to thereby cause a swirling of the liquid material in the container. The swirling of the liquid material tends to loosen any solid material or pigment which may have settled out, and to remix the same with the liquid material. It has been found that more rapid mixing can be achieved if the container is mounted on the housing 11 in an inverted position so that the solid material which has settled to the bottom of the container is located at the top during mixing.

The amount of orbital movement of the housing and container as well as the speed of the orbital movement is effected by the stiffness of the resilient posts 13; the mass of the moving parts Which includes the housing, clamp assembly, and container with the liquid material therein; the weight of the rolling weight element and the diameter of its circular raceway; and the pressure supplied to the nozzle to impel the rolling weight element. The mixing apparatus is primarily intended for use in automobile body shops for remixing the automotive finishes where the available air pressure supply is generally in the range of 60 to 100 p.s.i. The apparatus is intended for use in mixing both pint and quart size containers as shown in FIGURES 1 and 2 respectively. The pint size containers have a weight of approximately 1.2 pounds while the quart size containers have the weight of approximately 2.4 pounds. In order to minimize the change in the overall mass of the moving parts, when mixing liquid materials in different size containers, the housing and attached clamp assembly is preferably selected so as to have a weight substantially greater than the weight of the largest container and its contents to be mixed on the apparatus. For example, in a mixing apparatus for handling pint and quart size paint containers, it has been found satisfactory to use a housing having a weight of about five pounds. Thus, when mixing pint size containers, the overall weight of the moving mass including the housing, clamp assembly and the pint paint container is of the order of 6.5 pounds while the overall weight with a quart container is of the order of 7.75 pounds. However, the percentage change in the combined weight of the oscillating mass when mixing a pint container and a quart container is relatively small and less than 20%. The centrifugal force produced by the rolling weight element will obviously vary with the weight of the element, the diameter of its trackway, and the speed at which it is impelled around the trackway. With air pressure supplies commonly available in automobile refinishing shops, that is in the range of about 60- 100 p.s.i., it has been found satisfactory to use a rolling steel ball with a 1%," diameter and a weight of approximately four ounces moving in a circular raceway having an outer diameter of 4%". Excessive translatory movement of the container appears to impede good mixing action while also reducing the speed at which the ball is impelled around the circular raceway at a given supply pressure. Accordingly, the durometer of the posts 13 is selected so as to control the lateral movement of the housing under the centrifugal forces involved. Good results have been achieved using rubber posts of /8" diameter and 2% long and with a durometer of 65 to 75. Using posts of this type on the previously described housing it was found that the housing and a pint paint can would move in a generally circular orbit of about A" in diameter at around 1,450 r.p.m. with 60 p.s.i. supply pressure while a quart paint can at the same pressure would move in a circular orbit of around in diameter at 1,300 r.p.m. At p.s.i., the pint paint can would move in a circular orbit of around A" in diameter at about 1,680 r.p.m. While the quart paint can could move in a circular orbit of around A diameter at 1,350 r.p.m. Rapid mixing of the liquid vehicle and pigment was achieved at these speeds and orbital movements for both pint and quart containers.

From the foregoing it is thought that the construction and operation of the mixing apparatus will be readily understood. The container 19 containing the liquid material to be mixed is mounted on the housing 11 preferably with the container inverted and With the axis of the container adjacent to the axis of the circular trackway in the housing. The high pressure air, introduced through the inlet nozzle 16 produces a jet or stream that impels the rolling weight 15 around the circular raceway at a relatively high velocity and this produces an unsymmetrical centrifugal force which rotates in a generally horizontal plane and tends to shift the housing horizontally in a direction that follows the rotating centrifugal force. The posts 13 support the housing and the container for translatory movement in a generally horizontal orbit and this imparts a swirling motion to the liquid in the container for loosening and mixing the solid particles with the liquid vehicle.

While one particular embodiment of the invention has been described and illustrated, it is not intended that the invention be limited or confined to such disclosure but that changes and modifications may be made, incorporated, and embodied therein as desired within the scope of the appended claims.

What is claimed as new is:

1. An apparatus for stirring liquid materials in a container comprising a base, a housing, support means resiliently mounting said housing on said base for translatory movement in a generally horizontal orbit relative to the base, said housing defining an annular raceway with its axis disposed generally vertically, a rolling weight element in said raceway, said housing having orifice means for directing an air stream into said raceway in a direction to impel said rolling weight element around said raceway, said rolling weight element generating an unsymmetrical centrifugal force rotating in a generally horizontal plane and tending to shift said housing horizontally in a direction that follows the rotating centrifugal force, and means for mounting a container of liquid material on said housing for translatory movement therewith in a generally horizontal orbit.

2. An apparatus according to claim 1 wherein the container mounting means supports the container on the housing with the container axis disposed in the circle described by said annular raceway.

3. An apparatus according to claim 1 wherein the container mounting means supports the container on the housing with the container axis adjacent the axis of the annular raceway.

4. An apparatus according to claim 1 wherein the housing has a toroidal chamber therein defining said annular raceway.

5. An apparatus according to claim 4 wherein said toroidal chamber has a circular cross-section and said rolling weight element comprises a sphere having a diameter sufliciently smaller than the cross-section of said chamber to allow free rolling of the element therein.

6. An apparatus according to claim 1 wherein the support means includes a plurality of upright resilient post members attached to said base and said housing outwardly of the circle defined by said annular raceway.

7. An apparatus according to claim 6 wherein said post members include a section formed of an elastomeric material.

8. An apparatus according to claim 1 wherein said housing has a mass substantially greater than the mass of liquid material and container to be agitated.

9. An apparatus according to claim 1 wherein said housing has a container support surface on the upper side thereof, said means for mounting the container comprising a clamp for clamping the container to the support surface on the housing.

10. An apparatus for stirring liquid materials in the nature of paints, and the like contained in a cylindrical container comprising a housing defining an annular chamber and a container support surface on the upper side of the housing, a base, a plurality of generally upright resilient post members attached to said base and to said housing outwardly of said annular chamber for resiliently mounting the housing on the base for translatory movement in a generally horizontal orbit, said chamber defining an annular raceway with its axis disposed generally vertically, a rolling weight element in the form of a sphere in said raceway, said housing having orifice means for directing an air stream into said raceway in a direction to impel said rolling element around said raceway, salid rolling weight element generating an unsymmetrical centrifugal force rotating in a generally horizontal plane and tending to deflect said housing horizontally in a direction that follows the rotating centrifugal force, and means for clamping the cylindrical container on the support surface on the housing with the axis of the container adjacent to the axis of the raceway for translatory movement of the container with the housing in a generally horizontal orbit.

References Cited UNITED STATES PATENTS 2,255,799 9/1941 Meinzer 25972 2,469,525 5/1949 Skrob 25972 2,828,949 4/1958 Paladino 259--72 2,882,024 4/1959 Behrens 2591 3,157,389 11/1964 Williams 2591 3,159,384 12/1964 Davis 259-72 ROBERT W. JENKINS, Primary Examiner.

US. Cl. X.R. 214l75 

